A High Efficiency Two Stage 48V-12V DC-DC Isolated Converter

This article proposes an isolated two-stage DCDC converter for connecting the 48V bus and the 12V bus. The front stage is four-switch Buck-Boost (FSBB), simplified soft switching control can improve efficiency and has good dynamic response capability. The second stage is LLC resonance converter. The actual measurement results of the prototype show that it can achieve full-range soft switching, the full-load efficiency can reach 96%, and the maximum temperature at room temperature does not exceed 60°C.